Your cough is likely the result of irritating mucus or irritants in your throat or nose.
Most people who have these symptoms can relieve their persistent cough by using a combination antihistamine-decongestant medicine, because this can diminish allergy symptoms and reduce nasal mucus production. A prescription nasal spray containing a corticosteroid is another treatment that may help, and some people benefit from using the oral medicine montelukast (Singulair).
Contact your doctor if your cough does not completely resolve with over-the-counter antihistamine-decongestant products.